const proxyArr = new Proxy([1, 2, 3], {
   get(target, p, reciver) {
      // console.log(target, p, reciver);
      const len = target.length;
      if (p >= 0) {
         return target[p];
      } else if (p < 0 && -p <= len) {
         return target[len - (-p)]
      } else {
         return;
      }
   }
})

console.log(proxyArr[5]);
